Aug. 3 (UPI) -- Authorities arrested more than 600 people in an unauthorized opposition protest in Moscow on Saturday, a watchdog for detentions, OVD-Info, said.
Some journalists were among those arrested and there were at least six reports of police beatings, OVD-Info, which has a hotline for reporting detentions, said.
Russian officials said about 1,500 people attended the rally, vastly exceeding an earlier official statement that there had been only 350 attendees and 30 arrests.
Russian opposition leader Lyubov Sobol was also among the detained Saturday. Sobol was in a taxi about to go to the protest when police officers dragged her into a black van and sped off swiftly.
Sobol, also a lawyer and video blogger, is one of several opposition candidates election officials excluded from local elections scheduled for Sept. 8, prompting weeks of protests for free elections in the Russian capital.
Authorities said Sobol was arrested for violating regulations on street demonstrations. She has also been on a hunger strike for 21 days and called on other people to join the protest Saturday.
The authorities "are doing everything they can to try to intimidate the opposition," Sobol told independent broadcaster Dohd before her detention. "That is why it is important to come out today to show that Muscovites are not afraid of provocation and they are ready to stand up for their rights."
Hours after her arrest, Sobol tweeted from a police station that a dozen masked officers had driven her throughout Moscow for three hours prior to arriving there.
George Alburov, of the anti-corruption group FBK, which has links to prominent opposition leader Alexei Navalny, tweeted from a police vehicle that he had been arrested.
Alburov also tweeted a video of a battered man in the paddy wagon.
Shortly after Aluburov's arrest, Russian officials announced an investigation into FBK for alleged money laundering amounting to $15.3 million.
Authorities also detained scores of protesters last weekend.